U.S. patent number 8,873,426 [Application Number 12/499,906] was granted by the patent office on 2014-10-28 for wireless network connectivity in data centers.
This patent grant is currently assigned to NEC Laboratories America, Inc.. The grantee listed for this patent is Ravindranath Kokku, Rajesh Mahindra, Kishore Ramachandran, Sampath Rangarajan. Invention is credited to Ravindranath Kokku, Rajesh Mahindra, Kishore Ramachandran, Sampath Rangarajan.
United States Patent |
8,873,426 |
Ramachandran , et
al. |
October 28, 2014 |
Wireless network connectivity in data centers
Abstract
A method for wireless network connectivity in a data center
includes communicating between nodes in a data center across a
wireless interconnectivity through artificially created paths
between nodes in the data center, the nodes being at least one of a
server, router, switch, and other such components in the data
center that require connectivity; and managing the wireless
interconnectivity by a control and management entity.
Inventors: |
Ramachandran; Kishore (North
Brunswick, NJ), Kokku; Ravindranath (Monmouth Junction,
NJ), Mahindra; Rajesh (Monmouth Junction, NJ),
Rangarajan; Sampath (Bridgewater, NJ) |
Applicant: |
Name |
City |
State |
Country |
Type |
Ramachandran; Kishore
Kokku; Ravindranath
Mahindra; Rajesh
Rangarajan; Sampath |
North Brunswick
Monmouth Junction
Monmouth Junction
Bridgewater |
NJ
NJ
NJ
NJ |
US
US
US
US |
|
|
Assignee: |
NEC Laboratories America, Inc.
(Princeton, NJ)
|
Family
ID: |
42311651 |
Appl.
No.: |
12/499,906 |
Filed: |
July 9, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100172292 A1 |
Jul 8, 2010 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61079483 |
Jul 10, 2008 |
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Current U.S.
Class: |
370/254; 709/203;
370/328; 709/200 |
Current CPC
Class: |
H04W
84/10 (20130101) |
Current International
Class: |
H04L
12/28 (20060101); H04W 4/00 (20090101); G06F
15/16 (20060101) |
Field of
Search: |
;370/310,338
;709/203,223 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Renner; Brandon
Attorney, Agent or Firm: Kolodka; Joseph
Parent Case Text
This application claims the benefit of U.S. Provisional Application
No. 61/079,483, entitled "60 GHz Data-Center Networking:
Wireless--Worry less?" filed on Jul. 10, 2008, the contents of
which is incorporated by reference herein.
The present invention relates generally to wireless communications,
and more particularly, to using wireless communications for network
connectivity in data centers.
Claims
What is claimed is:
1. A method for wireless network connectivity in a data center
comprising the steps of: communicating between nodes in a data
center across a wireless interconnectivity through artificially
created paths between nodes in the data center, the nodes being
switches located in racks in the data center each connected to
servers in the rack; managing the wireless interconnectivity by a
control and management entity; said nodes are using a line-of-sight
wireless communication path or a non-line-of-sight wireless
communication path to enable communication of control and data
packets between said switches, said communication comprising
communication between switches on different racks; providing an
admission control entity performs network resource management in
order to map new services onto nodes to meet a quality of service;
scheduling traffic from distinct services at individual nodes to
maximize number of non-interfering transmissions per unit time
while meeting predetermined delay and bandwidth guarantees between
two nodes; and performing beam selection and steering and multi-hop
route computation to select beams for the said wireless
communication paths with a predetermined minimum interference to
other transmissions on other wireless communication path.
2. The method of claim 1, wherein the intermediate nodes form a
sequence of line-of-sight wireless links and at least one of the
intermediate nodes forms a line-of-sight wireless link with each of
the nodes.
3. The method of claim 1, wherein the control and management entity
comprises at least one of an alternate control plane connectivity,
a network virtualization at a control level, a network
virtualization at a node level and beam selection and steering on
the nodes.
4. The method of claim 3, wherein the alternate control plane
connectivity comprises an alternative connection to a 57-74 GHz
wireless spectrum connection to all nodes in the data center to
ensure a reliable control path between servers, and for failover,
that may not be possible always in the 57-74 GHz wireless
range.
5. The method of claim 4, wherein the alternate control plane
connectivity comprises one of an Ethernet, 802.11, or a low rate
channel in wireless high-definition HD to all nodes in the data
center.
6. The method of claim 3, wherein the network virtualization at a
control level comprises multihop routing computation to connect two
arbitrary nodes that cannot be directly connected.
7. The method of claim 3, wherein the network virtualization at a
control level comprises admission control in that data centers are
shared by multiple concurrently running services and the admission
control performs network resource management in order to map new
services onto the nodes such that the desired guarantees and
quality of service are met.
8. The method of claim 3, wherein the network virtualization at a
node level comprises security controls on each node to protect
content exchanged between two nodes from being decodable at other
nodes where transmitted signals reach.
9. The method of claim 3, wherein the network virtualization at a
node level comprises routing controls on each node to mask off from
the services the presence of multi-hop connectivity between two
servers.
10. The method of claim 3, wherein the beam selection and steering
comprises selecting the thinnest beam possible to ensure a
predetermined low level of interference to other transmissions with
time synchronization across the nodes ensuring co-ordination of
beam selection among different transmitting and receiving
nodes.
11. The system of claim 1, comprising time synchronizing across
nodes for coordination of beam selection among different
transmitting and receiving nodes.
12. A system for wireless network interconnectivity in a data
center comprising: wireless interconnectivity in a data center
through artificially created communication paths between nodes in
the data center, the nodes being switches located in racks in the
data center each connected to servers in the rack; and a control
and management entity for managing the interconnectivity and
network resource management to map new services onto nodes to meet
a quality of service and scheduling traffic from distinct services
at individual nodes to maximize number of non-interfering
transmissions per unit time while meeting predetermined
delay/bandwidth guarantees between two nodes; a line-of-sight
wireless communication path or a non-line-of-sight wireless
communication path to enable communication of control and data
packets between said switches, said communication comprising
communication between switches on different racks, wherein the
nodes perform beam selection and steering and multi-hop route
computation on individual nodes to select beams for the said
communication paths with a predetermined minimum interference to
other transmissions on other wireless communication paths.
13. The system of claim 12, wherein the wireless interconnectivity
comprises at least one of a line of site wireless communication
path and a non-line-of-sight path with a reflector.
14. The system of claim 12, wherein the control and management
entity comprises at least one of an alternate control plane
connectivity, a network virtualization module at a control level, a
network virtualization module at a node level and beam and
selection steering module.
15. The system of claim 14, wherein the alternate control plane
connectivity comprises an alternative connection to a 57-74 GHz
wireless spectrum connection to all nodes in the data center to
ensure a reliable control path between servers, and for failover,
that may not be possible always in the 57-74 GHz wireless
spectrum.
16. The system of claim 14, wherein the alternate control plane
connectivity comprises one of an Ethernet, 802.11 and a low rate
channel in wireless high-definition HD to all nodes in the data
center.
17. The system of claim 14, wherein the network virtualization
module at a control level comprises multihop routing computation to
connect two arbitrary nodes that cannot be directly connected.
18. The system of claim 14, wherein the network virtualization
module at a control level comprises admission control in that data
centers are shared by multiple concurrently running services and
the admission control performs network resource management in order
to map new services onto the nodes such that the desired guarantees
and quality of service are met.
19. The system of claim 14, wherein the network virtualization
module at a node level comprises security controls on each node to
protect content exchanged between two nodes from being decodable at
other nodes where transmitted signals reach.
20. The system of claim 14, wherein the network virtualization
module at a node level comprises routing controls on each node to
mask off from the services the presence of multi-hop connectivity
between two servers.
21. The system of claim 14, wherein the beam selection and steering
module comprises selecting the thinnest beam possible to ensure a
predetermined low level of interference to other transmissions with
time synchronization across the nodes ensuring co-ordination of
beam selection among different transmitting and receiving nodes.
Description
BACKGROUND OF THE INVENTION
In recent years, data centers have seen a significant growth due to
their cost effectiveness. With increased number of services hosted
in data centers, higher processing requirements for services (such
as web 2.0, search, GFS, MapReduce, etc.) and space constraints,
the density of servers per unit area has increased
significantly.
Traditionally, the servers in the data centers have been connected
by wires for networking. However, with increasing density of
servers and other devices within data centers, wired link
connectivity has led to denser cabling networks that engender
several challenges, e.g., FIG. 1. Apart from necessitating
significant manual effort in connecting these servers and keeping
accurate per-cable information for maintenance and troubleshooting,
these network cables additionally affect data center cooling. Cable
bundles behind/between server racks, even with structured cabling
such as in FIG. 2, or under raised floors can cause airflow
blockages leading to inefficient cooling and increased energy
consumption. Finally, cables take up substantial space, which can
otherwise be used for accommodating more servers.
Several data centers manage the ill-effects of unstructured
cabling, as shown in FIG. 1, by putting more structure, as in FIG.
2, and naming each wire carefully to locate quickly which two
points a wire connects. This structured cabling, however, still
requires significant manual effort, and causes issues with cooling.
For instance, FIG. 2 shows that even with structured cabling,
cables block the servers substantially making cooling of the
equipment difficult. Several third-party cabling services
specialize in designing structured wire placement that is tailored
to the requirements of a data center but unnecessary space is still
wasted and inefficient cooling still exists with these customized
cable structures.
Accordingly, there is a need for network connectivity in a data
center that reduces network cables, reduces complexity of setup and
maintenance of the data center as well as allowing for efficient
cooling requirements for components in the data center thereby
reducing energy use.
SUMMARY OF THE INVENTION
In accordance with the invention, a method for wireless network
connectivity in a data center includes communicating between nodes
in a data center across a wireless interconnectivity through
artificially created paths between nodes in the data center, the
nodes being at least one of a server, router, switch, and other
such components in the data center that require connectivity; and
managing the wireless interconnectivity by a control and management
entity. Preferably, the wireless interconnectivity includes the
wireless spectrum 57-74 GHz, at least one of a line of site
wireless communication path and a non-line-of-sight path with a
reflector, and the control and management entity comprises at least
one of an alternate control plane connectivity, a network
virtualization at a control level, a network virtualization at a
node level and beam selection and steering on the nodes.
In accordance with an alternative embodiment of the invention, a
system for wireless network interconnectivity in a data center
includes wireless interconnectivity in a data center through
artificially created communication paths between nodes in the data
center, the nodes being at least one of a server, router, switch,
and other such components in the data center that require
connectivity; and a control and management entity for managing the
interconnectivity.
BRIEF DESCRIPTION OF DRAWINGS
These and other advantages of the invention will be apparent to
those of ordinary skill in the art by reference to the following
detailed description and the accompanying drawings.
FIG. 1 illustrates current cable based network connectivity in a
data center.
FIG. 2 illustrates alternative current cable based network
connectivity in a data center.
FIG. 3 is a diagram of exemplary wireless network connectivity in
accordance with the invention.
FIG. 4 is a diagram of an exemplary architecture for wireless
network connectivity in accordance with the invention.
DETAILED DESCRIPTION
The invention is directed to using wireless technology in the 60
GHz range to connect servers, switches and other such components in
data centers, thereby reducing or eliminating network cables inside
a data center. Using wireless instead of wires for connectivity in
data centers reduces complexity of setup and maintenance of data
centers and reduces the cooling requirements of components. As a
result, it also reduces the cost of operating data centers. FIG. 3
is a diagram of exemplary wireless network connectivity in
accordance with the invention. FIG. 4 is a diagram of an exemplary
architecture for wireless network connectivity in accordance with
the invention.
The inventive connectivity in a data center achieves network
connectivity between several components in the data center through
wireless technology in the unlicensed spectrum between 57-64 GHz.
Radios operating in this band have unique characteristics that make
this invention a plausible solution. Regulations in this spectrum
allow a combination of large bandwidth (2500 MHz per channel) and
high allowable transmit power (up to 8 W), which implies that
speeds of up to multiple Giga bits per second can be achieved
reliably. The inherent directivity of transmissions at this
frequency results in reduced interference, increased isolation and
hence, improved security. Since the wavelength at these frequencies
is around five millimeters, antenna element sizes are
correspondingly small. This makes it possible to integrate the
entire transceiver, including the antennas, onto a single chip with
a small form-factor, a configuration not achievable by any other
wireless technology (such as 802.11) or system so far.
The diagram in FIG. 3 shows different instantiations of wireless
connectivity in data centers between servers, routers, switches and
other such components. In what follows, we will use the term node
to represent a server, router, switch, and other such components in
the data center that require connectivity. Nodes on different racks
16 can communicate through line-of-sight (LOS) path as in 11. Nodes
on the same rack may communicate through a reflector 10 as shown by
13. Due to space constraints, a LOS path may not be available for
several servers on different racks. To facilitate communication in
such scenarios, the data center may be provisioned with
rack-mounted, wall-mounted or ceiling-mounted reflectors 10. A
description of exemplary reflectors has been disclosed in European
Patent Application 07110884.9: (EP 1830488 A1), entitled, "Indoor
wireless communication system using active reflector, and
incorporated herein by reference. Such a path is shown as 12. In
scenarios where either a LOS path or a path through reflectors is
not available, multihop paths 17 through multiple intermediate
servers may be used. Nodes may be connected to the external
Internet using wires 15 through Gateway 14.
An exemplary architecture for carrying out the inventive wireless
network connectivity, as shown in FIG. 4, includes a number of
components: Nodes Synchronization 20, Network Virtualization 21 at
a control management level with scheduling, admission control and
route computation 211, a Control Plane 22, Network Virtualization
23 at a node level with security and routing functions 231, and a
beam selection and steering 24 component.
The control plane 22 with an alternative connectivity technology is
for exchanging information related to synchronization of the nodes
25; scheduling and routing of the various flows across the nodes.
The central control/management framework is also responsible for
admission control and resource management for the various services
running across the data center. Such centralized control
architecture eases design and manageability.
The Nodes Synchronization 20 across nodes helps schedule
transmissions. Time synchronization among the nodes helps schedule
collision-free transmissions on common wireless access
channels.
Beam Selection and Steering module 24. Initial beam selection and
steering on the individual nodes to select the thinnest beam
possible to ensure minimum interference to other transmissions.
Time synchronization across nodes will ensure co-ordination of beam
selection among different transmitting and receiving nodes.
Network virtualization at the control/management plane level 21.
Wireless network virtualization provides several components 211:
(a) Admission control: Data Centers are shared by multiple
concurrently running services. The admission control entity
performs network resource management in order to map new services
onto nodes such that the desired guarantees and quality of service
QoS are met. (b) Scheduling: Scheduling traffic from various
distinct services at individual nodes to maximize number of
non-interfering transmissions per unit time while meeting certain
delay/bandwidth guarantees between two nodes. And (c) Multi-hop
route computation to connect two arbitrary nodes that cannot be
directly connected:
Network virtualization 23 at the node level contains two modules
231: (a) security and (b) routing. Security techniques at the
virtual machine monitor (VMM) level protect content exchanged
between two servers from being decodable at other undesired nodes
where the transmitted signals reach. The routing module on each
node masks off from the services the presence of multi-hop
connectivity between two servers.
From the above description and associated FIG. 3-4, it can be seen
that the inventive use of wireless technology in the 57-64 GHz
spectrum for connectivity in data centers reduces or eliminates
cabling. The use of reflectors in data centers (on the walls, floor
and ceiling, in the racks, etc.) artificially creates paths between
two nodes in the data center that can be used for direct
connectivity. The inventive technique/system employs a
control/management entity for managing wireless connectivity
between nodes in the data center. The control/management entity
connects through an alternative technology such as wired Ethernet,
802.11, or a low rate channel in wireless HD, etc. to all nodes in
the data center. Alternative connectivity is to ensure a more
reliable control path between servers, and for failover, that may
not be possible always in the 60 GHz range. The invention includes
achieving network virtualization through operations at the
control/management entity. The invention includes determining a
schedule of non-interfering transmissions over a synchronized
slotted framework to ensure maximum number of non-interfering
transmissions per unit time while meeting certain delay/bandwidth
guarantees between two nodes. The invention use of wireless
multi-hop connectivity in data centers is effective in
non-line-of-sight environments.
The invention employs route computation to address the issue of
determining dynamically the best route to connect two servers using
a combination of multiple direct (point-to-point) connections
between servers. The invention employs restricting number of
services deployed on a node based on the effective performance
(such as bandwidth or delay) that can be guaranteed by network
virtualization. The invention includes virtualizing network
connectivity at the node level, using security techniques between
any two nodes in the data center to ensure that wireless
transmissions between any two nodes are not interpretable at other
nodes, and employs a routing module on each node to assist in
multihop routing. The nodes may use a routing protocol to relay
packets through multiple intermediate nodes.
The present invention has been shown and described in what are
considered to be the most practical and preferred embodiments. It
is anticipated, however, that departures may be made from herein
and that obvious modifications will be implemented by those skilled
in the art. It will be appreciated that those skilled in the art
will be able to devise numerous arrangements and variations, which
although not explicitly shown or described herein, embody the
principles of the invention and are within their spirit and
scope.
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